ISO INTERNATIONAL STANDARD 8598-1 First edition 2014-09-15 Optics and optical instruments Focimeters - Part 1: General purpose instruments Optique et instruments d'optique - Frontofocometres - Partie 1: Instruments pour cas généraux Reference number IS0 8598-1:2014(E) LSO IS02014 IHS under ted without license from IHS Not for Resale IS0 8598-1:2014(E) COPYRIGHTPROTECTEDDOCUMENT ISO2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyrightoffice Case postale 56:CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland @ IS0 2014 - All rights reserved No reproductic networking permited without license from IHS Not for Resale IS0 8598-1:2014(E) Contents Page Foreword ..iv Introduction ..V 1 Scope. .1 2 Normative references ..1 3 Terms and definitions ..1 4 Technical requirements for general purpose focimeters .3 5 Metrological requirements .5 5.1 General .5 5.2 Reference wavelength .5 5.3 Performance requirement .5 6 Test procedures. .8 6.1 General .8 6.2 Checking the indication errors. 8 6.3 Checking the axis marker for the optical centre of lens .8 6.4 Checking the alignment of the axis marker 9 6.5 Checking the adjusting rail .9 6.6 Checking the non-symmetric error for automated focimeters 9 6.7 Checking the repeatability of vertex power measurement for automated focimeters. .10 6.8 Checking for the centration error 10 6.9 Checking the capability of focimeters to measure tinted lenses 10 6.10 Checking the astigmatic axis repeatability for low-powered cylinder lens 10 6.11 Special procedures for eyepiece focimeters .11 6.12 Criterion for image focusing in manual focusing focimeters .11 7 Marking .11 7.1 Reference to IS0 8598-1 .11 7.2 Generalinformationtobesuppliedbythemanufacturer 11 7.3 Additional information to be supplied by the manufacturer .12 Annex A (informative) Use of correction values when measuring spectacle lenses ..13 Annex B (informative) Example for evaluation of uncertainty of measurement for automated focimeters for general use. ..18 Annex C (normative) Specifications of special reference lenses .24 Annex D (informative) Information for users on the performance ofgeneral purpose focimeters covered by this part of IS0 8598 .26 Bibliography .27 iii e with IS Not for Resale